Osoae bielschowski



. 225 Baum, and ten liters of water.

UNITED STATES PAENT OFFICE.

OSCAR BIELSGHOWfiKI, OF NEW YORK, N. Y.

DYEl NG COTTON FIBER.

SPECIFICATION forming part of Letters Patent No. 343,793, dated June1.5, 1886.

Application filed February 1, 1886. Serial No. 190,513. (SpecimensJ' Toall whom it may concern.-

Be it known that I, OSCAR BIELSOHOWSKI, of the city, county, and Stateof New York, have invented certain new and useful Improvements inProcesses of Dyeing Cotton and other Fibers, of which the following isaspecification.

This invention relates to a process for dyeing and printing cotton andother textile fabrics in a brown color, either by fixing thecoloring-matter directly on the fiber or by printing on the fabric anddeveloping the color by heat and moisture.

The invention consists of a process of dyeing cotton and other fibersand textile fabrics by steeping saidfibers or fabrics in a solution ofalpha-naphthylamine and slowly adding to said solution an oxidizingsolution for developing the color on the fibers.

In carrying out myinvention I prepare, first, a solution of one hundredgrams of commercial alpha-naphthylamine, and one hundred grams ofconcentrated hydrochloric acid of 22 to The materials to be dyed arefirst submitted to the usual preparatory treatment to adapt them toreceive dyes. They are then placed in the above describedalpha-naphthylaminesolution and allowed to remain long enough in thesame to become thoroughly impregnated therewith. An oxidizing solutionconsisting of one hundred grams of bichromate of potash, one hundredgrams of sulphuric acid of 66 Baum, and ten liters of water is thengradually added to the alpha-naphthylamine solution, care being takenthat the oxidizing solution is very slowly added, as the quick additionof the same would cause a precipitate of oxynaphthylamine, which has tobe avoided. The oxidizing bath develops the colors on the fibers, and isapplied at ordinary temperature. After the entire oxidizing solution hasbeen added to the alpha-naphthylamine solution the mixture isfinallyheated up to about Celsius, at which temperature the oxidationand the development of the color are entirely completed. The cotton orother materials are then washed, first in cold and afterward inhotwater, and finally again in hot Water to which a small quantity ofnatrium carbonate or soap has been added, that is afterward washed outagain.

If it be desired to carry out the oxidizing operation in a quickermanner, a solution of four hundred grams of alum and forty grams ofnatrium carbonate is dissolved in water, and four hundred grams ofacetate of lead added, which solution is heated for some time on a waterbath, so as to produce a solution of acetate of aluminum, which isdecanted from the sulphate of lead and diluted with as much water, sothat one liter is obtained. Of this solution two hundred and fifty gramsare added to the alpha-naphthylamine solution, whereby the oxidation ofthe same is accelerated when the oxidizing solution is added. Othermordants may be used for accelerating the oxidizing process.

In place of the oxidizing solution of bichromate of potash any otheroxidizing substance may be used.

In place of the alpha naphthylamine (O H, NHQ the derivatives of thesame-such as alpha-naphthylamine sulpho-acid (G H QIHQ SO,H)-may be usedfor imparting to cotton yarns, wool, and other textile fabrics a richbrown color.

For printing on fibers, one hundred grams of alpha-naphthylamine aremixed with thirty grams of concentrated sulphuric acid, and withasuitable mucilaginous substance, so asto produce a thick paste. Thispaste is printed on the fabric, so that the same can act on the fiber. Athickened mucilaginous solution of bichromate of potash is then printedon the layer of the alpha-naphthylamine, upon which the cotton or othertextile fabric is hung up in rooms heated by steam, so that the color isdeveloped in a short time by the influence of heat and moisture, afterwhich the fiber is dried and treated in the usual manner.

The process described produces a rich brown color on the fiber orfabrics, which can be varied in tints, and which resists the influenceof light, air, soap, and acids.

Having thus described my invention, I claim as new and desire to secureby Letters Patent The process herein described of dyeing or printingcotton or other textile fibers or he rics, which consists in steepingsaid fibers or fabrics-in a solution of alpha-naphthylamine, and thenadding to said solution an oxidizing solution, so as to develop thecolor on the fibers or fabrics, substantially as set forth.

In testimony that I claim the foregoing as It is hereby certified thatin Letters Patent No. 343,793, granted J une 15, 1886, upon theapplication of Oscar Bielschowski, of New York, New York, for animprovement in"Dyeing Cotton Fiber, an error appears in the printedspecification requiring the following correction, viz: In lines 38-9,page 1, the word oxynaphthylamine should read oxynaphthamine; and thatthe Letters Patent shonld. be read with this correction therein that thesame may conform to the record of the case in the Patent Ofiice.

Signed, countersigned, and sealed this 22d day of Jhne, A. D. 1886.

D. L. HAWKINS, Acting Secretary of the Interior,

[sEAL] Countersigned:

M. V MONTGOMERY,

Commissioner of Patents.

